This study examines the clinical features of heritable disorders of connective tissue as they pertain to the cardiovascular system. The disorders of interest are Marfan Syndrome, Ehlers-Danlos Syndrome (EDS) and Stickler Syndrome, as well as related disorders such as Familial Aneurysm Syndromes and Fibromuscular Dysplasia. To date, approximately 800 subjects have been enrolled in the study. The investigations include echocardiography, measurement of carotid intima thickness, measurement of ankle-brachial index and pulse wave velocity, MRI and MRA of the head and neck vessels and abdominal vessels. Novel findings include the increased incidence of brain aneurysms in patients with fibromuscular dysplasia, aortic root dilation in a subset of patients with Stickler Syndrome, and correlation of arterial dissections and aneurysms with endocrine and cytokine aberrations in patients with Vascular form of Ehlers Danlos Syndrome and Marfan Syndrome. The information obtained from this study will not only help the treatment of effected patients, but will also provide insights into the pathological processes of normal cardiovascular aging.